Collapsible and expandable tray assemblies for transporting and serving articles



Feb. 3, 1970 F. BUSSE ETAL 3,492,953

COLLAPSIBLE AND EXPANDABLE TRAY ASSEMBLIES FOR TRANSPORTING AND SERVINGARTICLES Filed June 4, 1968 5 Sheets-Sheet 1 Fig. 1

Inventors:

FriTz Hans PeTer MILLES b -mwam )heir' 14/ forney Feb. 3, 1970 F BUSSEETAL 3,492,953

COLLAPSIBLE AND EXPANDABLE TRAY ASSEMBLIES FOR THANSPORTING AND SERVINGARTICLES Filed June 4, 1968 5 Sheets-Sheet 2 Fig. 2 a 7 s T 21 WINS/L!23 1(2/ p 27 1h A 1 L T L i 1E, 16 15,16

Inventor:- FniTz BU Homs Paler MILLES by: M 0.

f/weir AHOMCI F. BUSSE ETAL 3,492,953 COLLAPSIBLE AND EXPANDABLE TRAYASSEMBLIES Feb. 3, 1970 FOR TRANSPORTING AND SERVING ARTICLES 5Sheets-Sheet 5 Filed June 4, 1968 lUM m B an b m A 3 M F'Ig6 Feb. 3,1970 F. BUSSE ETAL 3,492,953

COLLAPSIBLE AND EXPANDABLE TRAY ASSEMBLIES FOR TRANSPORTING AND SERVINGARTICLES Filed June 4, 1968 5 Sheets-Sheet 4 a 23 w W 25 Fig.9 1 27 Ma 6i i 11 C 12 Fig. 7

Inventors:

Fritz BUSSE Hans Pd'er by: m

Meir Aflomcy Feb. 3, 1970 F. BUSSE ETAL 3,492,953

COLLAPSIBLE AND EXPANDABLE TRAY ASSEMBLIES FOR TRANSPORTING AND SERVINGARTICLES Filed June 4, 1968 5 Sheets-Sheet 5 I II- II Inventors:

Hans PeTer MILLES Their Aflorney United States Patent Olfice 3,492,953Patented Feb. 3, 1970 Int. 01. A 171 3/08 US. Cl. 108111 Claims ABSTRACTOF THE DISCLOSURE A collapsible and expandable tray assembly forsupporting articles. The assembly includes a tray means which has ahorizontal operative position and which has in the region of its endsvertical wall portions formed with slots. At each of the opposed ends ofthe tray means are a pair of legs which have top ends located next toeach other and which in their expanded position diverge downwardly fromtheir top ends across the tray means. These pairs of downwardlydiverging legs are pivotally interconnected at their top ends so thatthey can be swung between their downwardly diverging expanded positionsto collapsed positions where they are located next to and aresubstantially parallel to each other. The pairs of legs respectivelycarry camming rods which respectively extend through the slots of thevertical wall portions of the tray means for camming the tray meansbetween its horizontal operative position and a collapsed positionextending substantially parallel to the legs when the latter are intheir collapsed position.

BACKGROUND OF THE INVENTION The present invention relates to trayassemblies for serving and transporting articles.

In particular, the present invention relates to that type of trayassembly which can be collapsed into a position of non-use where it willoccupy a relatively small volume and which can be expanded into anoperative position when the assembly is used.

Preferably the tray assembly of the invention includes a pair of upperand lower trays which are horizontal in their operative positions, andwhich are located between pairs of supporting legs pivotally connectedat their top ends and diverging downwardly from their top ends acrossthe ends of the trays, these legs being operatively connected at theirbottom ends to freely swingable rollers which enable the entire assemblyto be rolled for transporting the articles on the trays. When theassembly is collapsed the legs of each pair are located next to andextend substantially parallel to each other while the trays also assumepositions extending substantially parallel to the legs.

There are known assemblies of the above general type where pairs of legsare respectively situated at the ends of the assembly and are pivotallyconnected at their top ends, these legs being collapsible and formingwith a tray 'a substantially triangular end structure when expanded intotheir operative position. The trays which are carried by these legs areswingable with respect hereto while moving longitudinally along theselegs so that the elevations of the connections between the trays andlegs changes during displacement of the assembly between its collapsedand expanded positions.

One of the primary disadvantages of constructions of this latter type isthat it requires a relatively high degree of skill in the manipulationsperformed in order to displace the assembly between its collapsed andexpanded positions. In order to collapse the assembly it is firstnecessary to displace the trays manually, one after the other, fromtheir operative positions where they are held by detent structures, andit is only after these trays are thus manually displaced at least partof the way from their operative positions that it becomes possible toswing the legs at each end of the trays toward each other. Moreover,when the assembly is expanded, it is necessary to manually snap thetrays into their final positions where the detent structures maintainthe trays in their operative positions with the legs expanded. When thetrays are swung to their inoperative positions it is essential that thetrays be spaced from the floor by a distance greater than the width ofthe trays, so that it will be possible to conveniently engage the traysfor the purpose of again expanding the structure.

SUMMARY OF THE INVENTION It is accordingly a primary object of thepresent invention to provide a construction of the above general typewhich will avoid the drawbacks of the known structures.

Thus, it is an object of the invention to provide a tray assembly of theabove general type which can be operated in an extremely simple manner.

Also, it is the object of the invention to provide a structure of theabove type which occupies only a small amount of space while at the sametime making it possible to displace trays between operative andinoperative positions in response to and simultaneously with adisplacement of the legs of the assembly between their expanded andcollapsed positions.

Thus, it is a more particular object of the invention to provide a trayassembly of the above general type which may have upper and lower trayshaving operative horizontal positions and interconnected with end legassemblies which can be expanded for reliably holding the trays in theiroperative positions while at any time the leg assemblies can becollapsed with resulting displacement of the trays also to theircollapsed or inoperative positions where they extend substantiallyparallel to the collapsed legs and occupy with the latter an extremelysmall amount of space.

Thus, in accordance with the invention the assembly includes a traymeans having a pair of opposed ends and a centerline extendingperpendicularly across these opposed ends with the tray means having inthe region of its opposed ends wall portions which extend substantiallyvertically when the tray means is in its horizontal operative position,these wall portions respectively being formed with control slots. Ateach end of the tray means there are a pair of legs pivotallyinterconnected with each other over the tray means and divergingdownwardly from their top pivotal connections across each end of thetray means, these legs carrying rollers at their bottom ends. The legsare respectively fixedly connected with camming rods which respectivelyextend through slots parallel to the centerline of the tray means, theseslots terminate at each wall portion in inner ends situated in theregion of the centerline of the tray means. With this construction theslots are given a configuration which will result in swinging of thetray means between its horizontal operative position when the legsdiverge downwardly from their top pivotal connection and a collapsedposition. The camming rods coact with the slots to displace the traymeans from its horizontal operative position to a location where it issubstantially parallel to the legs.

BRIEF DESCRIPTION OF DRAWINGS This invention is illustrated by way ofexample in the accompanyingdrawings which formpart of thisapplicationand in which:

FIG. 1 is an end elevation of an assembly according tothe inventionshown in its expanded position;

FIG. 2 is a fragmentary front elevation of the assembly of FIG. 1 asseen from the left side of FIG. 1;

FIG. 3 is a fragmentary longitudinal partly sectional elevation taken atthe region of the top end of the assembly in a vertical plane extendingcentrally through an elongated tube whichinterconnects the pairs of endlegs; FIG. 4 is a transverse of fragmentary sectional elevation takenalongline IVIV of FIG. 3 in the direction 'of the arrows;

FIG. 5 is a fragmentary sectional plane view taken along line V-V ofFIG. 3 in the direction of the arrows;

FIG. 6 is a fragmentary front elevation showing the manner in which aleg is interconnected with a wall portion of a tray means;

FIG. 7 is a fragmentary longitudinal partly sectional elevation showingthe manner in which lower camming rods are interconnected with eachother;

FIG. 8 is an end elevation corresponding to FIG. 1

showing the structure between its collapsed and expanded positions;

FIG. 9 is also an end elevation corresponding to FIGS. 1 and 8 butshowing the structure in its fully collapsed condition.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, anassembly according to the invention is illustrated in FIG. 1 in itsexpanded position as it appears when looking toward one end of theassembly. FIG. 1 illustrates a pair of elongated legs 1 and 2, and it isto be understood that at the opposite end of the assembly which is notvisible in FIG. 1 there are a corresponding pair of legs 3 and 4situated behind the legs 1 and 2. Thus, the legs 1 and 2 form one pairof legs situated at one end of the assembly, and legs 3 and 4 form asecond pair of legs situated at the opposite end of the assembly. Attheir lower ends these respectively carry freely swingable rollers 5 ina well known manner. It will be noted that at the region of their bottomends all of the legs are respectively provided with angled portionswhich extend vertically, in the expanded position of the assembly, downto the location where these bottom vertical leg portions are connectedto the roller units 5.

Each pair of legs fixedly carries an upper pair of camming rods 6 and 7,respectively, so that a pair of the rods 6 are affixed to the legs 1 and3 and extend therefrom horizontally toward each other, these rods beingcoaxial, while a pair of the rods 7 are respectively fixed to and extendtoward each other from the legs 2 and 4, with these cam- ,ming rods 7also having a common horizontal axis and being parallel to and situatedat the same elevation as the rods 6, as is apparent from FIGS. 1 and 2.

The assembly includes an upper tray means 12 having a tray provided witha bottom flat wall having an upwardlydirected surface and a lowersurface in the operative horizontal position of the tray means 12 shownin FIGS. 1 and2. Fixed to the lower surface of the tray means 12 are apair of vertical wall portions 10 forming part of angled membersextending transversely across a longitudinal centerline of the traymeans 12 which extends perpendicularly across the opposed ends of thetray means 12 midway between its front and rear side edges, and ofcourse, also midway between the legs 1 and 2, as well as the legs 3 and4, when these legs are in their expanded positions. The pair of verticalwall portions 10 are respectively formed with a pair of slots 9 whichare aligned with each other and which are of identical configuration,each of these slots 9 are being formed intermediate its ends with astepped portion 8. The pair of camming rods 6 respectively extendthrough the slots 9. In addition, these vertical wall portions 10 arerespectively formed with identical and aligned slots 11 through which-the camming rods-7respectively. extend. It will be noted that with thisconstruction it is these camming rods 6 and 7 which serve to support thetray means 12 on the legs 14. At each wall portion 10 the slots 9 and 11have inner end regions situated at the region of the centerline of thetray means 12 and overlapping each other in the manner indicated mostclearly in FIG. 1. As is apparent from FIG. 2, the vertical wallportions 10 are situated inwardly of the opposed ends of the tray means12 in the general region of these opposed ends.

In order to avoid longitudinal shifting of the tray means 12 along thecamming rods '6, 7, the latter rods carry spacer sleeves 13 which extendbetween the legs and the wall portions 10 in the manner shown in FIGS. 2and 6. These spacer sleeves 18 may, for example, be in the form of hosesections through which the camming rods 6, 7 respectively extend in themanner shown in FIGS. 2 and 6.

A lower tray means 14 is situated beneath the tray means 12, and thelegs 1 and 3 respectively fixedly carrying camming rods 15 which extendstoward each other along a common horizontal axis and pass through a pairof slots 17 formed in vertical wall portions 18 of the lower tray means14. These wall portions 18 have with respect to the tray means 14 thesame relative locations that the wall portions 10 have with respect tothe tray means 12, and the pair of slots 17 are of an identicalconstruction and are aligned with each other. The vertical wall portions18 are also formed with elongated slots 19 which are identical andaligned with each other, and the legs 2 and 4 respectively fixedly carrycoaxial camming rods 16 which extend horizontally through the slots 19.Thus, these rods 15 and 16 also serve to support the tray means 14 onthe legs 1-4. It is to be noted that the slots 17 and 19 also overlapeach other in the region of the centerline of the tray means 14. Thislongitudinal centerline of the tray means 14 extends perpendicularlyacross the opposed ends thereof and perpendicularly across the verticalwall portions 18 of the tray means centrally between the pairs of legswhen the latter are in their expanded positions shown in FIG. 1. Thepair of slots 17 and 19 of each wall portion 18 which overlap each otherin the region of the tray centerline at the inner ends of the slots haveouter ends which are inclined upwardly at different angles, FIG. 1indicating the outer end regions 17 and 19' of the slots 17 and 19 whichare inclined upwardly at different angles.

As is apparent particularly from FIG. 7, the pair of coaxial cammingrods 15 extend all the way along the tray means 14 and abut directlyagainst each other, and in the same way the pair of camming rods 16extend into abutting relation. A sleeve 20 surrounds the abutting endregions of the coaxial rods 15 and an identical sleeve 20 surrounds theabutting end regions of the coaxial rods 16. The pair of rods 15 areformed in the region of their abutting ends with recesses 22 whichreceive dimples 21 formed in the sleeve 20 surrounding the ends of therods 16. Thus, with this construction the pair of rods 15 are fixedlyconnected to each other to form in effect a single elongated rodextending'between and fixed to the legs 1 and 3, and the pair of rods 16form in effect a single elongated rod extending between and fixed to thelegs 2 and 4, so that in this way the rigidity of the structure isenhanced.

Referring now to FIGS. 3-5, it will be seen that the several legs 1-4are respectively provided at their top ends with angled portionsextending horizontally and forming horizontal free end portions for theseveral legs, these portions being parallel to the centerline of thetray means. Thus, FIG. 5 indicates the horizontal angled portions 3 and4' of the legs 3 and 4, and the legs 1 and 2 are provided with similarhorizontal angles portions respectively extending toward the angledportions 3' and 4'.

For the purpose of pivotally interconnecting each pair of legs at theregion of their top ends, the angled horizontal top free end portions ofeach pair of legs are received in a tube 23 which in cross section has asubstantial elliptical or oval configuration, as shown most clearly inFIG. 4. One of the horizontal free end portions of each pair of legs isprovided with an extension which extends across and substantially fillsthe interior of the tube 23. In the example illustrated in FIGS. 3-5, itis the horizontal end portion 3' of the leg 3 which is provided with theextension 24 which substantially fills out the interior of the tube 23in the manner shown most clearly in FIG. 4. The extension 24 may form anintegral part of the end portion 3 extending angularly from the innerend thereof across the interior of the tube 23 in the manner shown mostclearly in FIG. 5. It is to be understood that at the other end of thetube 23 the leg 1 will have a horizontal free end portion received inthe tube 23 and having a transverse extension identical with theextension 24.

The horizontal portion 4 of the leg 4 is formed with a notch 25 throughwhich the free end of the extension 24 extends, so that the horizontalportion 4' of the leg 4 has in effect a substantially hook-shaped freeend straddling the extension 24 in the manner shown most clearly in FIG.3. As is shown in FIG. 4, the downwardly directed surface of the notch25 which is formed in the end portion 4' of the leg 4 is inclined withrespect to the upwardly directed surface of the extension 24 which isreceived in the notch 25 to provide clearance sufficient to enable thepair of legs 3 and 4 to be swung with respect to each other betweentheir collapsed and expanded positions. In the same way, at the otherend of the tube 23 the horizontal end portion of the leg 2 is formedwith a notch corresponding to the notch 25 and receiving the extensionof the leg 1 which corresponds to the extension 24.

In order to fix the horizontal upper free end portions of the severallegs in the elongated interconnecting tube 23 which forms a meanspivotally interconnecting these legs, so that the elongated free endportions of the legs cannot be axially displaced out of the ends of thetube 23, the lower wall portion of the latter is formed at each of itsend regions with a pair of inwardly extending dimples 26 receivedbetween the free end portions of the legs in the manner shown in FIG. 5,and these dimples will reliably retain the upper horizontal end portionsof the legs within the tube 23 while at the same time the legs areturnable with respect to the tube 23. These dimples 26 are formed onlyafter the parts are assembled. However, it is also possible tointerconnect the components by other means. Thus, for example, theextension 24 may be welded or soldered to the tube 23, and this willalso result in retaining of the legs operatively connected with respectto each other and with the tube 23 while the legs are still turnablewith respect to each other since the extension 24 does not move withrespect to the tube 23.

At each end of the tube 23 there is an elongated springy wire 27 havingan upper horizontally extending portion 27 extending along the interiorof the tube 23 of each and of its end regions and having an exteriordownwardly directed portion. These downwardly directed portions of thesprings 27 respectively coact with the legs 2 and 4 so as to urge themaway from the legs 1 and 3, respectively. Thus, the downwardly directedparts 27' of the springs 27 extend respectively along the inner surfacesof the upper portions of the legs 2 and 4 and in part around the latterat the lower ends of the springs 27. These springs 27 serve to urge thestructure towards its expanded condition and thus facilitate expandingof the structure from its collapsed toward its expanded condition.

The above-described structure operates as follows:

Assuming that it is desired to collapse the structure from the expandedposition thereof shown in FIG. 1, then the parallel legs 2 and 4 aresimultaneously swung inwardly toward the centerline of the pair of traymeans 12 and 14 and toward the other parallel legs 1 and 3.

As a result the coaxial rods 16 move longitudinally along the slots 19because the outer end portions 19 of the slots 19 are upwardly inclinedto a lesser extent than the outer end portions 17' of the slots 17, sothat there is less resistance to longitudinal displacement of the rods16 along the slots 19 than of the rods 15 along the slots 17. Thus, therods 16 will approach the central region of the verticalwall portions18. After rods 16 move beyond the centerline of the tray means 14, thelatter swings downwardly as a result of its own weight, andsimultaneously with this action the rods 7 move toward the inner ends ofthe slots 11 to the central region of the vertical wall portions 10 soas to bring about, at the same time, a downward tilting of the traymeans 12.

During the continued inward swinging of the parallel legs 2 and 4, theinner ends of the slots 11 and 19 form stops which engage and turn aboutthe camming rods 7 and 16, and the upper tray means 12 is shown in thisposition in dot-dash lines in FIG. 8. Thus, because of the engagement ofthe rods 7 and 16 with the inner ends of the slots 11 and 19 the trays12 and 14 will be displaced with respect to the rods 6 and 15 with theinner ends of the slots 9 and 17 approaching the rods 6 and 15.

Because of the intermediate step region 8 of the slots 9, the upper traymeans 12 swings ahead of the lower tray means 14 so that the upwardlyswinging end of the latter will not strike against the tray means 12,Thus, the stepped portions of the slots 9 coact with the rods 6 toaccelerate the swinging of the tray means 12 with respect to theswinging of the tray means 14. In this way the swinging of the trayscontinues until the structure has the collapsed condition indicated inFIG. 9 where the legs are located next to and extend substantiallyparallel to each other while the tray means 12 and 14 extendsubstantially parallel to the legs and overlap each other in the mannershown in FIG. 9.

The expanding of the structure from the position of FIG. 9 back to theposition of FIG. 1 is aided by the force of the springs 27, The movementof the tray means 12 and 14 is controlled by the configuration of theslots and their camming action with the camming rods so that simply inresponse to movement of the legs between their collapsed and expandedpositions the tray means 12 and 14 will assume their horizontaloperative positions. In some cases it may be desirable, at leastinitially, to provide a manual starting movement for the tray means 12and 14, preferably after the pair of tray means has the central regionof the ends thereof engaged by the legs 2 and 4 and is situated in ahorizontal position when the structure is collapsed.

Thus, as a result of the above-described structure of the invention, theentire assembly is extremely simple and convenient to operate. Becauseof the camming action provided by the camming rods in coaction with theslots of the tray means the movement of the tray means between theiroperative and collapsed conditions is controlled solely in response toswinging of the legs between their collapsed and expanded positions.Therefore, the manipuations are extremely simple to carry out, and nospecial dexterity is required. The distance of the lower tray means fromthe floor and also the distance between the pair of tray means can bemaintained very small. The control of the movement of the trays isdetermined in part by the different inclinations of the outer ends 17'and 19' of the slots 17 and 19.

By providing the upper slots 9 with the intermediate steps 8, both ofthe trays will move in substantially the same way during collapsing ofthe structure at the initial part of the collapsing movement while as aresult of the intermediate step 8 of each slot 9 the upper tray means 12is accelerated in advance of the lower tray means so that the pair oftray means cannot strike against each other.

The situation of the angled members 10 and 18 as shown in FIG. 2 anddescribed above provides advan- 7 tages with respect to the assembly andthe manufacture thereof. H

The extension of the pairs of camming rods and 16 into abuttingengagement as described above makes it possible to provide the assemblywith a sufiiciently great stability without requiring additionalstiffening members for this purpose.

Also, the above-described structure in connection with the coupling ofthe pairs of rods to each other in the end portions of theinterconnecting tube 23 provides a simple and eifective means to achievethe pivotal interconnection of the pairs of rods so that they can bedisplaced from expanded positions where they diverge downwardly fromtheir top ends to their collapsed positions where they extendsubstantially parallel to each other as shown in FIG. 9.

What is claimed is:

1. A collapsible and expandable assembly for transporting and servingarticles, comprising at least one tray means having a substantiallyhorizontal operative position and having a pair of opposed ends and acenterline extending longitudinally of said tray means substantiallyperpendicularly across said opposed ends thereof substantially midwaybetween side edges each of which extends between said opposed ends ofsaid tray means, said tray means having in the regions of the saidopposed ends wall portions respectively extending vertically when saidtray means is in said substantially horizontal operative positionthereof, said wall portions extending perpendicularly with respect tosaid centerline and each being formed with a pair of longitudinal guideslots respectively having inner ends located adjacent to each other inthe region of said centerline, a pair of substantially uprightsupporting legs situated at each end of said tray means and extendingabove and below the latter, each pair of supporting legs having top endsadjacent to each other substantially over said centerline of said traymeans and, when the latter is in said operative position thereof, eachpair of legs diverging downwardly from their top ends to an elevationbelow said tray means where each pair of legs terminate in bottom endsspaced from each other by a distance greater than at any other part ofeach pair of legs, means interconnecting each pair of legs at said topends thereof for swinging movement with respect to each other about anaxis parallel to said centerline to a collapsed position where said legsof each pair are substantially parallel to and located next to eachother, and a pair of camming rods respectively fixed to the legs of eachpair extending parallel to said centerline, and respectively extendingthrough the pair of slots of each vertical wall portion, the cammingrods fixed to one of said pair of legs extending through the slots ofthe wall portion of the tray means adjacent to said one pair of legs andthe camming rods of the other pair of legs extending through the slotsof the wall portion of the tray means adjacent to the other of said pairof legs, and said camming rods coacting with said slots for tilting saidtray means from said operative substantially horizontal position thereofto a position where said tray means extends substantially parallel tosaid legs when the latter are in their collapsed position located nextto and extending substantially parallel to each other.

2. The combination of claim 1, and wherein said legs at the ends of saidtray means respectively carry rollers at their bottom ends.

3. The combination of claim 1 and wherein inner ends of said slots ofeach vertical wall portion of said tray means overlap each other.

4. The combination of claim 1 and wherein there are a pair of tray meansspaced one above the other when in their' substantially horizontaloperative positions, both of said tray means having said vertical wallportions each of which is formed with said pair of slots and said legsfixedly carrying camming rods respectively extending through all of saidslots for displacing said tray means between said operative positionswhen said legs are expanded and diverged downwardly with respect to eachother from their top ends to collapsed positions where said pair of traymeans are substantially parallel to said legs with the latter situatednext to and extending substantially parallel to each other.

5. The combination of claim 4 and wherein said tray means overlap eachother when in their collapsed positions.

6. The combination of claim 1 and wherein said slots of each wallportion respectively terminate in outer end regions which are upwardlyinclined at different angles.

7. The combination of claim 4 and wherein said upper tray means has oneof said slots of each wall portion thereof formed with an intermediatestep.

8. The combination of claim 1 and wherein said tray means includes atray having a flat supporting wall having upper and lower surfaces, anda pair of angle members fixed to said lower surface of said wall andextending therealong transversely to said centerline and respectivelyhaving said vertically extending wall portions ex tending downwardlyfrom said lower surface of said wall and formed with said slots, saidangled members being situated inwardly of-said opposed ends of said traymeans in the region of said opposed ends.

9. The combination of claim 4 and wherein the camming rods which extendsthrough said slots of said wall portions of the lower one of said traymeans extend all the way across the space between the pairs of legs,abut against each other, and are fixedly connected together.

10. The combination of claim 1 and wherein each pair of legs is providedat its top end with inwardly extending portions extending angularly fromsaid legs parallel to said centerline, said means pivotallyinterconnecting said pairs of legs at said top ends thereof including anelongated tube of substantially oval cross section extending betweensaid pairs of legs and receiving said inwardly extending end portionsthereof, one of said legs having at its inwardly extending portion atransverse extension extending across the interior of said tube and theother of said inwardly extending portions of the other one of each pairof legs being formed with a notch receiving said extension of said oneinwardly extending portion so that said legs are pivotallyinterconnected by the location of said extension in said notch with saidlegs each being turnable with respect to said tube.

References Cited UNITED STATES PATENTS 2,720,402 10/1955 De Puy et al108-1 11 XR 2,844,257 7/ 1958 Friedman 108112 3,097,748 7/1963 Drabertet al 108--112 3,148,746 9/1964 Jueulano.

3,436,092 4/1969 Werner 108115 XR BOBBY R. GAY, Primary Examiner G. O.FINCH, Assistant Examiner

